Recent advances in cuprous oxide thin film based photovoltaics

Thin film based photovoltaics is the promising alternative to the Si-based solar cells for the widespread use of solar energy. Cu 2 O, owing to its binary nature, is a strong contender to replace the quaternary and environmentally toxic absorber layers. The maximum laboratory efficiency recorded so far for Cu 2O- based solar cells is ∼8%. With the rapid evolution in thin film based deposition techniques, there is a good scope that the efficiency for Cu 2O- based solar cells can be enhanced to match with its other counterparts. In the present review, we have elucidated the developments in the field of Cu 2O- based photovoltaics in the last decade. The various strategies adopted by the scientific community to enhance the conversion efficiency of conventional Cu 2 O/ZnO heterojunction-based solar cell have been illustrated. The widely reported alternative buffer layers to reduce the band offset with the Cu 2 O absorber layer is discussed in detail. The current status on the possibility of realizing n -type conductivity in the native p -Cu 2 O with an aim to fabricate the corresponding homojunction–based solar cells has also been presented. Finally, the future direction for enhancement in the device performance has been proposed in terms of the modification in the growth techniques. • Developments in the field of Cu 2 O based photovoltaics in the last decade • Various problems associated with the conventional Cu 2 O/ZnO heterojunction • Alternative buffer layers for Cu 2 O based photovoltaics • Current status on the n-type Cu 2 O for possible homojunction